Hi,

I performed a diazonium coupling reaction that resulted in the formation of Methyl Red in my lab.

At one point near the end of the experiment, a 10% aqueous NaOH solution was added to the reaction vessel containing Anthranyl diazonium chloride and N,N-dimethylaniline. I know this is done because the formation of the azo compound is a very slow reaction and the rate of Methyl red formation is increased by raising the pH of the solution.

However, my question is...

Why is this this necessary? In orther words, how does the pH of the solution affect the reactivity of the N,N-dimethylaniline reagent?

Thank you for you time,

-R